NGC 1333, also known as the Embryo Nebula, is a reflection nebula located 967 light-years away in the northern constellation Perseus. The nebula is an active star-forming region within the larger Perseus molecular cloud. It contains young star clusters that are still embedded in their birth clouds.
The open clusters in the Embryo Nebula are divided into two sub-groups. One sub-group lies in the northern part of the nebula and the other in the southern. Those in the southern part contribute the most to the nebula’s infrared emission. The designation NGC 1333 is used both for the nebula and the associated cluster.
Many of the stars in the young clusters are still in the pre-main sequence stage of their evolutionary cycle. They are still accreting mass from their surrounding envelopes of gas and dust. These stars will eventually contract to the main sequence and start burning hydrogen.
This image of NGC 1333 was produced by the Agrupació Astronòmica d’Eivissa (AAE) using 303 photographies taken by the Cala d’Hort Telescope (TCH) in Ibiza island, Spain. Credit: Wiimedia Commons/Alpratsibz (CC BY-SA 4.0)
The reflection nebula has a total mass of around 450 solar masses. The open cluster contains around 150 stars and has a mass of 100 solar masses. The median age of the stars in the region is only 1 million years.
The young stellar objects in the Embryo Nebula are producing jets and bipolar outflows. Some are associated with Herbig-Haro objects. These are smaller patches of nebulosity that form when jets of partially ionized gas expelled by stars collide with the surrounding gas and dust clouds.
The brightest Herbig-Haro objects in the region are catalogued as HH 5, HH 6, HH 7-11, and HH 12. They were discovered by the American astronomer George Herbig on photographic plates in 1974.
In this image the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top centre of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth. Herbig-Haro objects like HH 7–11 are transient phenomena. Travelling away from the star that created them, at a speed of up to 250,000 kilometres per hour they disappear into nothingness within a few tens of thousands of years. The young star that is the source of HH 7–11 is called SVS 13 and all five objects are moving away from SVS 13 toward the upper left. The current distance between HH 7 and SVS 13 is about 20,000 times the distance between Earth and the Sun. Herbig–Haro objects are formed when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds. The Herbig–Haro objects visible in this image are no exception to this and were formed when the jets from the newborn star SVS 13 collided with the surrounding clouds. These collisions created the five brilliant clumps of light within the reflection nebula. Image credit: ESA/Hubble & NASA, K. Stapelfeldt (CC BY 4.0)
NGC 1333 lies in the western portion of the Perseus molecular cloud (PMC, PerMCld), a giant molecular cloud approximately 1,000 light-years away. The cloud is a large stellar nursery that stretches across an area 6 by 2 degrees across. It is mostly invisible at optical wavelengths, but appears very bright in the mid- and far-infrared band. The star-forming regions NGC 1333 and IC 348 are the only visible parts of the cloud. Both NGC 1333 and other parts of the Perseus molecular cloud produce mostly low-mass stars.
NGC 1333 is associated with a dark cloud catalogued as Barnard 205 (L1450). The cloud extends from the nebula about a degree to the south. The nebula and the cloud lie at the northern end of a ridge of CO emission on the west side of a large cavity in the Perseus molecular cloud.
A collection of gas and dust over 500 light-years across, the Perseus Molecular Cloud hosts an abundance of young stars. It was imaged here by the NASA’s Spitzer Space Telescope. Image credit: NASA/JPL-Caltech (PD)
The Embryo Nebula is one of the best-studied objects of its type. Estimates of the distance to the nebula are in the range from 980 to 1,140 light-years. The smaller value of 967 light-years comes from a 2018 study of open cluster kinematics based on the data in Gaia Data Release 2 (Gaia DR2).
The hot, blue, chemically peculiar star BD +30°549 is responsible for illuminating the nebula. It has the spectral type B8. A 2023 study determined an age of around 2.7 million years and an effective temperature of 13,100 ± 100 K for the star.
BD +30°549 is either a pre-main sequence star or a zero-age main sequence (ZAMS) star, one that has just begun hydrogen fusion. Like many other members of the NGC 1333 cluster, it hosts a circumstellar disk.
Astronomers have identified 20 young stellar objects that produce outflows in the nebula, as well as 95 X-ray sources and several dozen brown dwarfs. More than a dozen planetary-mass objects (PMOs) with a spectral type M9 or later have been discovered in the nebula.
In 2023, observation with the Spitzer Space Telescope revealed that about 42 percent of these objects were surrounded by a circumstellar disk. Only one of the six lowest-mass objects with a spectral type L0 or later was found to have a disk. The astronomers found that the lowest-mass free-floating objects with confirmed disks have masses of around 0.01 solar masses (around 10 Jupiter masses). The study, led by Aleks Scholz of the School of Physics & Astronomy, University of St Andrews, UK, was published in The Astronomical Journal.
In 2024, observations with the NIRISS (Near Infrared Imager and Slitless Spectrograph) instrument aboard the James Webb Space Telescope (JWST) revealed additional planetary mass objects in the nebula. A study led by Adam B. Langeveld of the Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, confirmed the spectral types for 19 known brown dwarfs in the nebula and detected six new candidate L-type dwarfs with estimated masses between 5 and 15 times that of Jupiter. One of these PMOs, designated NIRISS-NGC1333-5 (NN5), was found to have a mass of around 5 Jupiter masses and a circumstellar disk. It is the candidate for the lowest mass object known to have a disk.
This stunning new mosaic of images from the NASA/ESA/CSA James Webb Space Telescope showcases the nearby star-forming cluster, NGC 1333. The nebula is in the Perseus molecular cloud, and located approximately 960 light-years away. Webb’s superb sensitivity allows astronomers to investigate young objects with exceptionally low masses. Some of the faintest ‘stars’ in the picture are in fact newly born free-floating brown dwarfs with masses comparable to those of giant planets. The same cluster was featured as the 33rd anniversary image of the NASA/ESA Hubble Space Telescope in April of 2023. Hubble’s image just scratched the surface of this region, because clouds of dust obscure much of the star formation process. Observing with a larger aperture and in the infrared part of the spectrum, Webb is capable of peering through the dusty veil to reveal newborn stars, brown dwarfs and planetary mass objects. The centre of the image presents a deep peek into the heart of the NGC 1333 cloud. Across the image we see large patches of orange, which represent gas glowing in the infrared. These so-called Herbig-Haro objects form when ionised material ejected from young stars collides with the surrounding cloud. They are hallmarks of a very active site of star formation. Many of the young stars in this image are surrounded by discs of gas and dust, which may eventually produce planetary systems. On the right hand side of the image, we can glimpse the shadow of one of these discs oriented edge-on — two dark cones emanating from opposite sides, seen against a bright background. Similarly to the young stars in this mosaic, our own Sun and planets formed inside a dusty molecular cloud, 4.6 billion years ago. Our Sun didn’t form in isolation but as part of a cluster, which was perhaps even more massive than NGC 1333. The cluster in the mosaic, only 1–3 million years old, presents us with an opportunity to study stars like our Sun, as well as brown dwarfs and free-floating planets, in their nascent stages. Image credit: ESA/Webb, NASA & CSA, A. Scholz, K. Muzic, A. Langeveld, R. Jayawardhana (CC BY 4.0)
Facts
NGC 1333 was discovered by the German astronomer Eduard Schönfeld, assistant to Friedrich Wilhelm Argelander, on December 31, 1855. The nebula was included in the Bonner Durchmusterung (BD), an astrometric star catalogue prepared by Argelander, Schönfeld and Adalbert Krüger, and published by the Bonn Observatory from 1859 to 1863.
American astronomer Horace Tuttle observed the nebula on February 5, 1859. German astronomer Arthur von Auwers also spotted it before 1862.
American astronomer Edwin Hubble was one of the first to study the nebula. He included NGC 1333 in a catalogue of nebulae used to study the distribution and stellar content in galactic nebulae.
In 2007, NASA’s Spitzer Space Telescope detected the presence of water vapour in the young star system NGC 1333-IRAS 4B. Astronomers reported that the water vapour was pouring down from the star system’s birth cloud into the dusty disk where planets may be forming.
The Spitzer observations provided the first direct look at the way that water is delivered to the region where planets form. The ice from the outer envelope of the embryonic star system falls towards the star and vaporizes as it hits the disk of planet-forming materials. The water vapour will eventually freeze into comets and asteroids.
NASA’s Spitzer Space Telescope observed a fledgling solar system, like the one depicted in this artist’s concept, and discovered deep within it enough water vapor to fill the oceans on Earth five times. This water vapor starts out in the form of ice in a cloudy cocoon (not pictured) that surrounds the embryonic star, called NGC 1333-IRAS 4B (buried in center of image). Material from the cocoon, including ice, falls toward the center of the cloud. The ice then smacks down onto a dusty pre-planetary disk circling the stellar embryo (doughnut-shaped cloud) and vaporizes. Image credit: NASA/JPL-Caltech (PD)
This diagram illustrates the earliest journeys of water in a young, forming star system. Stars are born out of icy cocoons of gas and dust. As the cocoon collapses under its own weight in an inside-out fashion, a stellar embryo forms at the center surrounded by a dense, dusty disk. The stellar embryo “feeds” from the disk for a few million years, while material in the disk begins to clump together to form planets. NASA’s Spitzer Space Telescope was able to probe a crucial phase of this stellar evolution – a time when the cocoon is vigorously falling onto the pre-planetary disk. The infrared telescope detected water vapor as it smacks down on a disk circling a forming star called NGC 1333-IRAS 4B. This vapor started out as ice in the outer envelope, but vaporized upon its arrival at the disk. By analyzing the water in the system, astronomers were also able learn about other characteristics of the disk, such as its size, density and temperature. How did Spitzer see the water vapor deep in the NGC 1333-IRAS 4B system? This is most likely because the system is oriented in just the right way, such that its thicker disk is seen face-on from our Earthly perspective. In this “face-on” orientation, Spitzer can peer through a window carved by an outflow of material from the embryonic star. This system in this drawing is shown in the opposite “edge-on” configuration. Credit: NASA/JPL-Caltech (PD)
Location
The Embryo Nebula lies in the southern part of the constellation Perseus, near the border with Aries and Taurus. It appears in the region between the Pleiades in Taurus and Algol in Perseus, near the third magnitude blue supergiant star Zeta Persei and the fainter blue giant Atik (Omicron Persei).
NGC 1333 location, image: Stellarium
NGC 1333 can be spotted in small telescopes, but only appears as a hazy patch. Telescopes with larger apertures reveal a pair of dark nebulae, catalogued as Barnard 1 and Barnard 2.
The best time of the year to observe NGC 1333 and other deep sky objects in Perseus is during the month of December, when the constellation appears higher in the sky around 9 pm. At declination +31°, the Embryo Nebula is visible from locations north of the latitude 59° S. It is best seen from the northern hemisphere.
Embryo Nebula – NGC 1333
| Constellation | Perseus |
| Object type | Reflection nebula |
| Right ascension | 03h 29m 11.3s |
| Declination | +31° 18′ 36″ |
| Apparent magnitude | 5.6 |
| Apparent size | 6′ x 3′ |
| Distance | 967 light-years (296.5 parsecs) |
| Names and designations | Embryo Nebula, NGC 1333, Ced 16, LBN 741, LBN 158.31-20.44, GN 03.26.1, DG 18, GRS G158.30 -20.50, Theia 21 |
Images
Astronomers are celebrating the NASA/ESA Hubble Space Telescope’s 33rd launch anniversary with an ethereal photo of a nearby star-forming region, NGC 1333. The nebula is in the Perseus molecular cloud, and is located approximately 960 light-years away. Hubble’s colourful view, showcasing its unique capability to obtain images in light from ultraviolet to near-infrared, unveils an effervescent cauldron of glowing gases and pitch-black dust stirred up and blown around by several hundred newly forming stars embedded within the dark cloud. Even then, Hubble just scratches the surface; most of the star-birthing firestorm is hidden behind clouds of fine dust — essentially soot — that are thicker toward the bottom of the image. The black areas of the image are not empty space, but are filled with obscuring dust. To capture this image, Hubble peered through a veil of dust on the edge of a giant cloud of cold molecular hydrogen — the raw material for fabricating new stars and planets under the relentless pull of gravity. The image underscores the fact that star formation is a messy process in a rambunctious Universe. Ferocious stellar winds, likely from the bright blue star at the top of the image, are blowing through a curtain of dust. The fine dust scatters the starlight at blue wavelengths. Farther down, another bright super-hot star shines through filaments of obscuring dust, looking like the Sun shining through scattered clouds. Credit: NASA, ESA, STScI (CC BY 4.0)
Embryo Nebula (NGC 1333), image credit: Adam Block and Sid Leach/Mount Lemmon SkyCenter/University of Arizona (CC BY-SA 3.0 US)
This image of NGC 1333 was taken using the Mosaic-1 imager and the National Science Foundation’s Mayall 4-meter telescope at Kitt Peak. This star-forming region, located roughly 1,000 light-years from Earth in the direction of the constellation Perseus, harbors hundreds of newly formed stars less than one million years old. Many of these proto-stars exhibit energetic activity such as jets and strong stellar winds. Image credit: T.A. Rector/University of Alaska Anchorage, H. Schweiker/WIYN and NOIRLab/NSF/AURA (CC BY 4.0)
NGC 1333 is a region towards the constellation of Perseus that harbors newly formed stars less than one million years old. The density of gas and dust in this region is great enough to cause many different effects of illumination and emission. On the left side of this image the light of bright star is scattered and looks primarily blue. Other stars barely make there presence known due to the enveloping clouds of gas and dust. There are also several stellar outflows from the baby stars in this image and regions where the gas is glowing strongly red due to the copious amount of radiation some of these stars release.This image was taken as part of Advanced Observing Program (AOP) program at Kitt Peak Visitor Center during 2014. Credit: KPNO/NOIRLab/NSF/AURA/Jay Lavine and Ali Huang/Adam Block (CC BY 4.0)
NGC 1333, image credit: NASA/CXC/JPL (CC BY 2.0)